The invention relates to electrical contacts and more particularly to contacts adapted for slidably electrically contacting a conductive surface.
The invention further relates to contacts of the nature described wherein said contacts include means for preventing transfer of material from the contact's engagement arm onto a noble metal segment positioned on said arm, said segment provided to enhance the electrical connection between the contact and the conductive surface.
The invention still further relates to contacts of the above variety wherein said contacts are adapted for use within a printed circuit board connector.
An inherent disadvantage of electrical contacts which slidably contact a conductive surface and which include thereon a noble metal segment is the inability of such members to prevent transfer of the contact's material into the segment during said sliding engagement. The transfer of the arm's material adversely affects the electrical conductive properties of the noble metal segment due to the formation of a film or similar layer of the lesser conductive material thereon.
Previous techniques to prevent material transfer, as indicated in U.S. Pat. No. 3,585,573, have included providing the upper portion of the arm with a plurality of indentations, holes, or projections which aligned on the arm above the noble segment. While these techniques may have somewhat reduced the arm material transfer onto the noble metal segment or button, several disadvantages were inherent. Providing these features on or within the contact's arm necessitated at least one additional manufacturing step, thus adding not only to the time required to manufacture the contacts but also to the cost thereof. Furthermore, the added material used in such features as projections was itself capable of "wiping" onto the noble button. Even further, these projections also proved capable of defacing the respective conductive surface to which electrical contact was made.
It is believed therefore that an improved electrical contact which includes means for preventing material transfer onto the contact's noble metal segment in a more advantageous manner than the above known components would constitute an advancement in the art.
It is further believed that a printed circuit board connector incorporating the above contact would also constitute an advancement in the art.